Lens used for improving diffraction efficiency of blue-ray disc and China high definition disc

Abstract

The utility model relates to a lens used for improving the diffraction efficiency of a blue-ray disc and a China high definition disc, which comprises a first lens surface (1) and a second lens surface (2), wherein the first lens surface is a free curved surface, and the second lens surface is an aspheric surface; the first lens surface and the second lens surface are used for focusing incident light into a focal zone; and the focal zone comprises an information recording layer (31) focused on the blue-ray disc, and an information recording layer (41) focused on the China high definition disc. Due to a phase control structure, the diffraction efficiency of the lens corresponding to the blue-ray disc and the China high definition disc can be improved, the energy loss is reduced, and the stray light is improved. 本实用新型涉及一种用于增强蓝光光盘和中国高清光盘衍射效率的透镜，包括第一透镜面(1)和第二透镜面(2)，第一透镜面为自由曲面，第二透镜面为非球面。第一透镜面和第二透镜面将入射光聚焦到聚焦区，聚焦区内包括聚焦在蓝光光盘信息记录层(31)和中国高清光盘信息记录层(41)。通过相位控制结构使得透镜对应蓝光光盘和中国高清光盘的衍射效率得到提升，降低能量损耗和改善杂散光产生。